Exposure to family conflict and violence can have negative behavioral, psychological, and physiological consequences for children's development. Research with older children finds that exposure to family conflict has a negative impact on the ability to regulate emotions, hut also that effective emotion regulation serves as a buffer against the negative behavioral consequences of exposure to family conflict. By examining early effects of exposure to inter-adult anger at a time when emotion regulation systems are developing rapidly, we. hope to elucidate mechanisms of risk and resilience that may account for differential outcomes. Specific aims are to examine the early effects of exposure to inter-adult anger on infants' behavioral and physiological emotion regulation and on mother-infant affective interactions. Sixty male and female infants (ages 3-6 mos) will be randomly assigned to one of three inter-adult emotion exposure conditions: angry, neutral, or excited. Infant positive and negative affective behaviors, direction of gaze/attention. and self-soothing behaviors will he coded. RSA suppression, an index of vagal regulation of cardiac functioning will be measured. These behavioral and physiological responses will be compared among the three conditions. To assess the effect of inter-adult anger on infants' ability to engage in mutually positive and regulated social interactions, infants will be observed in face-to-face interactions with their mothers after emotion exposure. Joint positive affect and mutual responsiveness will be observed and compared among the three emotion conditions. To assess the effect of inter-adult anger on infants' abilities to regulated emotion in response to social disruption, infants will be observed in a maternal still-face condition and behavioral and physiological responses will be compared among the three conditions. Individual differences in infants' responses to inter-adult anger will he examined in relation to maternal report of current conflict in the home and maternal report of infant temperamental reactivity. Results will provide a foundation for a program of longitudinal research on the role of emotion regulation in mediating children's adjustment to inter-adult conflict and violence.